The American hunk revealed the couple -who are raising six kids, adopted children Maddox, nine, Pax, seven, and Zahara, six, as well as biological children Shiloh, five, and two-year-old twins Knox and Vivienne - would think about tying the knot if their youngsters want them to.
He said: "The kids ask about marriage. It`s meaning more and more to them. So it`s something we`ve got to look at. If Angie and I feel it`s important for the kids, then we`ll get married."
The 47-year-old actor - who starred alongside Angelina in `Mr. and Mrs. Smith` - also explained becoming a father has changed the way he makes choices in life.
He added: "I think that after becoming a father, I am changing in my choices. Today, everything I do, I look at in the context of what my kids are going to see and feel. I think about everything I do now - what my kids are gonna see, how they`re gonna feel.
"But I think they know me as a dad; I hope they would just think I`m a pretty damn good actor."